Conventionally, a vehicle such as automotive vehicle is equipped with a wiper apparatus which ensures a field of view from a driver and an occupant through a windshield. A motor device having an output shaft to be rotated in normal and reverse directions is used as a driving source for such a wiper apparatus. This motor device causes a wiper member to oscillate in a given wiping range and wipe rainwater, etc., away from the windshield.
The wiper member includes a wiper arm attached to a vehicle body in such a way as to oscillate freely, and a wiper blade fitted to the front end side of the wiper arm. The wiper blade has a blade rubber whose lip is pressed to the surface by the spring force of a tensile spring disposed on the base end of the wiper arm. This prevents the blade rubber from lifting apart from the surface under the influence of wind, etc., caused by the vehicle's traveling, thereby ensuring better wiping performance.
On the other hand, the spring force of the tensile spring keeps the lip tilted when the wiper blade is in a stopped state. If the wiper blade is not used for a long period, therefore, the blade rubber deforms plastically, posing a problem that the wiping performance of the blade rubber drops significantly. In order to solve the above problem, for example, Japanese Patent Application Laid-Open Publication No. 2013-163454 discloses a technique which periodically changes a direction of the front end side of the lip to suppress the plastic deformation of the blade rubber.
A technique disclosed in Japanese Patent Application Laid-Open Publication No. 2013-163454 includes a control unit (controller) which controls an output shaft of a wiper motor to cause the output shaft to rotate in normal and reverse directions. When an ignition switch is switched on or off, the control unit moves the wiper blade between a first stop position and a second stop position in each case. This causes the front end side of the lip to change the direction it faces, thus suppressing the plastic deformation of the blade rubber.